Processing apparatus

ABSTRACT

A processing apparatus includes a chuck table configured to hold a plate-shaped workpiece thereon, a processing unit including a spindle having an end portion at which a processing tool for grinding or polishing a workpiece held on the chuck table is to be mounted, a processing room surrounded by a wall and configured to accommodate the chuck table and the end portion of the spindle therein, and a dirty situation indication unit configured to indicate a degree of adhesion of processing waste, which is generated by grinding or polishing of the workpiece, to the wall. The dirty situation indication unit includes a transmission window made of a member that passes visible rays therethrough and configuring part of the wall, and a color sample indication unit indicative of a relationship between an amount of the processing waste adhering on the transmission window and a color of the transmission window.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a processing apparatus for processing a plate-shaped workpiece.

Description of the Related Art

Opportunities to process a wafer, a package substrate or the like before it is divided into device chips to make it thin in order to reduce the size and weight of device chips to be incorporated into an electronic apparatus or the like are increasing. For such processing, a processing apparatus is used which includes a spindle (rotary shaft) on which a processing tool such as, for example, a grinding wheel, a polishing pad or the like is to be mounted. By contacting the processing tool, which is rotated by the spindle, with a workpiece such as a wafer, a package substrate or the like, the workpiece can be processed thin.

Incidentally, if a workpiece is processed by such a processing apparatus as described above, then a large amount of processing waste (dust) is generated and scatters to the surroundings. Therefore, a method has been proposed by which a cover that covers an end portion of a spindle, on which a processing tool is to be mounted, is provided on a processing apparatus such that a workpiece is processed in a processing room surrounded by the cover (for example, refer to Japanese Patent Laid-Open No. 2004-1118). According to this method, generated processing waste does not scatter to the outside of the cover.

SUMMARY OF THE INVENTION

If a cover that covers an end portion of a spindle is provided on a processing apparatus as described above, then processing waste adheres and gradually accumulates on an inner wall of the cover. If the processing waste accumulated on the inner wall of the cover drops from some reason and enters a gap between the processing tool and the workpiece, then the workpiece will get big scratches. Therefore, it is necessary to clean the inner wall of the cover at an appropriate timing.

However, since the timing for cleaning is determined, for example, on the basis of experience or the like of an operator, the frequency of cleaning sometimes becomes unnecessarily high, resulting in degradation of the operating rate of the processing apparatus. On the other hand, if a timing for cleaning is delayed, then processing waste may drop from the inner wall of the cover and enter a gap between the processing tool and the workpiece, resulting in big scratches to the workpiece.

Therefore, it is an object of the present invention to provide a processing apparatus that makes it possible to appropriately decide the degree of adhesion of processing waste to a wall that surrounds a processing room in which an end portion of a spindle is accommodated.

In accordance with an aspect of the present invention, there is provided a processing apparatus including a chuck table configured to hold a plate-shaped workpiece thereon, a processing unit including a spindle having an end portion at which a processing tool for grinding or polishing the workpiece held on the chuck table is to be mounted, a processing room surrounded by a wall and configured to accommodate the chuck table and the end portion of the spindle therein, and a dirty situation indication unit configured to indicate a degree of adhesion of processing waste, which is generated by grinding or polishing of the workpiece, to the wall, in which the dirty situation indication unit includes a transmission window made of a member that passes visible rays therethrough and configuring part of the wall, and a color sample indication unit provided in an overlapping relationship with the transmission window or adjacent the transmission window and indicative of a relationship between an amount of the processing waste adhering on the transmission window and a color of the transmission window.

Since the processing apparatus according to the aspect of the present invention includes the dirty situation indication unit that in turn includes the transmission window made of a member that passes visible rays therethrough and the color sample indication unit indicative of a relationship between an amount of the processing waste adhering on the transmission window and a color of the transmission window, by visually comparing the transmission window and the color sample indication unit with each other, the degree of adhesion of the processing waste to the wall surrounding the processing room can be decided appropriately.

The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood, from a study of the following description and appended claim with reference to the attached drawings showing a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view schematically depicting an example of a configuration of a polishing apparatus; and

FIG. 2 is a plan view schematically depicting an example of a configuration of a dirty situation indication unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following, an embodiment of the present invention is described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view schematically depicting an example of a configuration of a polishing apparatus (processing apparatus) 2 according to the present embodiment. As depicted in FIG. 1, the polishing apparatus 2 includes a base 4 that supports the components thereof. A wall-shaped support structure 6 is provided at a rear end of the base 4. An opening 4 a is formed at a front portion of an upper face of the base 4, and a transport unit 8 for transporting a plate-shaped workpiece 11 is disposed in the opening 4 a.

The workpiece 11 is, for example, a disk-shaped wafer made of a material such as silicon (Si). However, there is no restriction to the material, shape, structure, size and so forth of the workpiece 11. For example, a substrate made of a material such as a different semiconductor, a ceramics, a resin, a metal or the like can be used for the workpiece 11.

In regions on the sides of the opening 4 a, cassettes 10 a and 10 b for accommodating workpieces 11 are placed. Behind the region in which the cassette 10 a is to be placed, a centering mechanism 12 is provided. The centering mechanism 12 adjusts the position of the center of a workpiece 11 transmitted, for example, from the cassette 10 a by the transport unit 8.

A loading unit 14 that pivots with a workpiece 11 held thereon is provided behind the centering mechanism 12. Behind the loading unit 14, another opening 4 b is formed. In this opening 4 b, an X-axis moving table 16, an X-axis moving unit (not depicted) for moving the X-axis moving table 16 in an X-axis direction (forward and rearward direction) and a dustproof drip-proof cover 18 that covers the X-axis moving unit are disposed.

The X-axis moving unit includes a pair of X-axis guide rails (not depicted) extending in parallel to each other in the X-axis direction, and the X-axis moving table 16 is mounted for sliding movement on the X-axis guide rails. A nut portion (not depicted) is provided on a lower face side of the X-axis moving table 16, and an X-axis ball screw (not depicted) extending in parallel to the X-axis guide rails is held in meshing engagement with the nut portion. An X-axis stepping motor (not depicted) is connected to one end portion of the X-axis ball screw. The X-axis stepping motor rotates the X-axis ball screw to move the X-axis moving table 16 in the X-axis direction along the X-axis guide rails. On an upper face of the X-axis moving table 16, a chuck table 20 for sucking and holding a workpiece 11 is provided.

The chuck table 20 is connected to a rotational driving source (not depicted) such as a motor such that it rotates around an axis of rotation extending substantially in parallel to the Z-axis direction (vertical direction). Further, the chuck table 20 is moved, by the X-axis moving unit described above, between a loading/unloading region on the front side into and from which a workpiece 11 is loaded and unloaded and a polishing region on the rear side in which the workpiece 11 is polished. An upper face of the chuck table 20 serves as a holding face to and on which a workpiece 11 is sucked and held. This holding face is connected to a suction source (not depicted) through a flow path (not depicted) formed in the inside of the chuck table 20. A workpiece 11 loaded onto the chuck table 20 by the loading unit 14 is sucked and held by a negative pressure of the suction source acting on the holding face.

On a front face of the support structure 6, a Z-axis moving unit 22 is provided. The Z-axis moving unit 22 includes a pair of Z-axis guide rails 24 extending in parallel to the Z-axis direction, and a Z-axis moving plate 26 is attached for sliding movement to the Z-axis guide rails 24. A nut portion (not depicted) is provided on a rear face side (back face side) of the Z-axis moving plate 26, and a Z-axis ball screw 28 extending in parallel to the Z-axis guide rails 24 is held in meshing engagement with the nut portion. A Z-axis stepping motor 30 is connected to one end portion of the Z-axis ball screw 28. The Z-axis stepping motor 30 rotates the Z-axis ball screw 28 to move the Z-axis moving plate 26 in the Z-axis direction along the Z-axis guide rails 24.

A polishing unit (processing unit) 32 for polishing a workpiece 11 is provided on a front face (surface) of the Z-axis moving plate 26. The polishing unit 32 includes a tubular spindle housing 34 fixed to the Z-axis moving plate 26. A spindle 36 serving as a rotary shaft is accommodated in the inside of the spindle housing 34. A disk-shaped mount 38 is fixed to an end portion (lower end portion) of the spindle 36 that is exposed from the spindle housing 34, and a polishing pad (processing tool) 40 of a diameter substantially equal to that of the mount 38 is mounted on a lower face of the mount 38. In the present embodiment, the polishing pad 40 for dry polishing for which polishing liquid such as slurry is not used is used. However, a polishing pad 40 for wet polishing may be used instead.

To a base end side (upper end side) of the spindle 36, a rotational driving source (not depicted) such as a motor is connected such that the polishing pad 40 is rotated by force transmitted from the rotational driving source. Further, the polishing unit 32 is moved down by the Z-axis moving unit 22 described hereinabove to press the polishing pad 40 against an upper face (polishing object face) of a workpiece 11 held on the chuck table 20.

At a position adjacent the loading unit 14, an unloading unit 42 that pivots with a workpiece 11 held thereon is provided. In front of the unloading unit 42 but behind the region in which the cassette 10 b is placed, a washing unit 44 for washing a workpiece 11 after polished is disposed. The workpiece 11 washed by the washing unit 44 is transported by the transport unit 8 and is accommodated, for example, into the cassette 10 b. In front of the opening 4 a, an operation panel 46 for inputting a condition for polishing and so forth is installed.

When a workpiece 11 is to be polished by the polishing apparatus 2, in a state in which the workpiece 11 is sucked to and held by the chuck table 20, the chuck table 20 and the polishing pad 40 are rotated relative to each other and the polishing pad 40 is pressed against the upper face of the workpiece 11. Consequently, the workpiece 11 can be polished. It is to be noted that, although, in the present embodiment, polishing liquid such as slurry is not used, polishing liquid may otherwise be used.

If the workpiece 11 is polished by the polishing pad 40 as described hereinabove, then dust is liable to scatter to the surroundings of the chuck table 20 or the polishing pad 40. Therefore, the polishing apparatus 2 of the present embodiment includes a cover 52 that covers the chuck table 20 and an end portion (polishing pad 40) of the spindle 36. A processing room (polishing room) in which a workpiece 11 is to be polished is formed by the cover 52. In particular, the processing room is surrounded by a wall 52 a that configures the cover 52. Further, the chuck table 20 and an end portion of the spindle 36 are accommodated in the processing room. There is no special restriction to the material, shape and so forth of the cover 52. For example, metal such as stainless steel, aluminum or the like can be used to form the cover 52.

An exhaust port (not depicted) extending through the cover 52 between the inside and the outside is formed in part of the wall 52 a of the cover 52. An exhaust duct 54 disposed outside the cover 52 is connected at one end thereof to the exhaust port. Further, a suction source 56 is connected to the other end of the exhaust duct 54. In other words, the suction source 56 is connected to the exhaust port through the exhaust duct 54. The suction source 56 has a control switch 58 for controlling generation of suction force. By operating the control switch 58, it is possible to allow the exhaust port to be acted upon by suction force of the suction source 56. When the workpiece 11 is to be polished, the suction force of the suction source 56 is caused to act upon the exhaust port such that air including processing waste. (dust) in the processing room is exhausted to the outside of the cover 52.

In the polishing apparatus 2 configured in such a manner as described above, processing waste generated upon polishing stays in the processing room and does not scatter to the outside of the cover 52. Meanwhile, on the inner side face of the wall 52 a that configures the cover 52, processing waste adheres and gradually accumulates. If the processing waste accumulating on the wall 52 a of the cover 52 drops from some reason and enters the gap between the polishing pad 40 and the workpiece 11, the workpiece 11 will get big scratches.

Therefore, in the polishing apparatus 2 of the present embodiment, a dirty situation indication unit 60 for indicating a degree of adhesion of processing waste on the wall 52 a is provided at part of the wall 52 a that configures the cover 52. FIG. 2 is a plan view schematically depicting an example of a configuration of the dirty situation indication unit 60. As depicted in FIG. 2, the dirty situation indication unit 60 includes a transmission window 62 that is a member such as a glass plate or the like that passes visible rays therethrough. The transmission window 62 is fitted in an opening extending through the cover 52 between the inner side and the outer side and configures part of the wall 52 a. In a situation in which processing waste adheres and accumulates on the inner side face of the wall 52 a, processing waste similarly adheres and accumulates also on the inner side face of the transmission window 62. If processing waste adheres and accumulates on the inner side face of the transmission window 62, then the transmittance of the transmission window 62 drops. Therefore, if the state of the transmission window 62 is confirmed, then it can be decided to what degree adhesion and accumulation of processing waste on the wall 52 a proceed.

At a position overlapping with the transmission window 62 or at a position adjacent the transmission window 62, a color sample indication unit 64 that indicates a relationship between the amount of processing waste adhering and accumulating on the transmission window 62 and the color (transmittance) of the transmission window 62 is provided. Further, adjacent the color sample indication unit 64, a comment 66 according to the amount of processing waste adhering and accumulating on the transmission window 62 is applied. However, the comment 66 may be omitted. The color sample indication unit 64 includes a first indication portion 64 a indicative of a color corresponding to the color of the transmission window 62 in a state in which no processing waste adheres and accumulates, and a second indication portion 64 b indicative of a color corresponding to the color of the transmission window 62 in a state in which processing waste adheres and accumulates a little. The color sample indication unit 64 further includes a third indication portion 64 c indicative of a color corresponding to the color of the transmission window 62 in a state in which much processing waste adheres and accumulates, and a fourth indication portion 64 d indicative of a color corresponding to the color of the transmission window 62 in a state in which very much processing waste adheres and accumulates.

Further, alongside of each of the first indication portion 64 a, second indication portion 64 b, third indication portion 64 c and fourth indication portion 64 d, a comment 66 is applied. For example, alongside the first indication portion 64 a, the comment 66 of “OK” indicating that there is no necessity to perform cleaning as yet is applied. Alongside the second indication portion 64 b, the comment 66 of “Now is cleaning time” indicating that it is desirable to perform cleaning now is applied. Alongside the third indication portion 64 c, the comment 66 of “Cleaning as early as possible is desirable” indicating that cleaning is required is applied. Further, alongside the fourth indication portion 64 d, the comment 66 of “Clean immediately” indicating that processing waste adhering and accumulating on the wall 52 a may cause a problem with high possibility.

Now, a method of confirming the degree of adhesion of processing waste on the wall 52 a using the dirty situation indication unit 60 is described. First, an operator will visually compare the transmission window 62 and the color sample indication unit 64 with each other at an arbitrary timing and determine to the color of which one of the first indication portion 64 a, second indication portion 64 b, third indication portion 64 c and fourth indication portion 64 d the color of the transmission window 62 is close. Consequently, the degree of adhesion of processing waste to the wall 52 a becomes obvious.

For example, in the case where the color of the transmission window 62 is close to the color of the first indication portion 64 a, it can be recognized that little processing waste adheres and accumulates on the wall 52 a. On the other hand, for example, in the case where the color of the transmission window 62 is close to the color of the second indication portion 64 b, it can be recognized that a little processing waste adheres and accumulates on the wall 52 a. Further, in the case where the color of the transmission window 62 is close to the color of the third indication portion 64 c or the fourth indication portion 64 d, it can be recognized that much processing waste adheres and accumulates on the wall 52 a. Thus, the operator can consider the comment 66 or the like applied alongside the color sample indication unit 64 to determine a timing at which the cover 52 is to be cleaned.

In this manner, since the polishing apparatus (processing apparatus) 2 of the present embodiment includes the dirty situation indication unit 60 that in turn includes the transmission window 62 that is a member that passes visible rays therethrough and the color sample indication unit 64 indicative of a relationship between the amount of processing waste adhering on the transmission window 62 and the color of the transmission window 62, by visually comparing the transmission window 62 and the color sample indication unit 64 with each other, the degree of adhesion of processing waste on the wall 52 a surrounding the processing room can be decided appropriately.

It is to be noted that the present invention is not limited to the description of the embodiment and so forth but can be carried out in various modified manners. For example, although the embodiment described above is directed to the polishing apparatus 2 that polishes a plate-shaped workpiece 11, the processing apparatus of the present invention may be a grinding apparatus that grinds a plate-shaped workpiece 11. In the grinding apparatus, for example, a grinding wheel (processing tool) including a grindstone is mounted on a disk-shaped mount fixed to an end portion of a spindle.

Further, while, in the embodiment described hereinabove, the color sample indication unit 64 is configured from the first indication portion 64 a, second indication portion 64 b, third indication portion 64 c and fourth indication portion 64 d for indicating four different states, the color sample indication unit in the present invention may be configured otherwise by an indication unit that indicates two, three, five or more different states.

The present invention is not limited to the details of the above described preferred embodiment. The scope of the invention is defined by the appended claim and all changes and modifications as fall within the equivalence of the scope of the claim are therefore to be embraced by the invention. 

What is claimed is:
 1. A processing apparatus, comprising: a chuck table configured to hold a plate-shaped workpiece thereon; a processing unit including a spindle having an end portion at which a processing tool for grinding or polishing the workpiece held on the chuck table is to be mounted; a processing room surrounded by a wall and configured to accommodate the chuck table and the end portion of the spindle therein; and a dirty situation indication unit configured to indicate a degree of adhesion of processing waste, which is generated by grinding or polishing of the workpiece, to the wall, wherein the dirty situation indication unit includes a transmission window made of a member that passes visible rays therethrough and configuring part of the wall, and a color sample indication unit provided in an overlapping relationship with the transmission window or adjacent the transmission window and indicative of a relationship between an amount of the processing waste adhering on the transmission window and a color of the transmission window. 